If the people involved were negligent in their ways of operations in such a way that the accident could have been prevented
(thinking out loud here)
Negligence might be tough to prove, ( I'm in court alot for insurance claims) Something makes me think that the FAA was involved in the safety aspect of the placement of the seating at the show and certain requirements that they (the people running the show) must meet for the seating. (Ill be truthful, I'm not sure where i heard this, but for the life of me i remember hearing something of the sort.
Blacks Law dictionary defines Negligence as ......n. The failure to exercise a standard of care that a reasonably prudent person would have exercised in the same or similar situation. Conduct that falls below the standard established by law for the protection of others against unreasonable risk of harm. The quality or state of being negligent; lack of due diligence or care; omission of duty; habitual neglect; heedlessness. An act or instance of negligence or carelessness.
Not sure if they can be found negligent if they took all means reasonably necessary to protect people, coupled with the FAA requirements, no history of habitual neglect, and in following all the rules that were given to them (FAA), they did their due diligence.
All that said, a lawyer can make an argument that a zebra is purple if he wants. Ive seen it first hand. I once saw an attorney make an argument for his case citing the movie "Starman" with Jeff Bridges.......It was all I could do (and our corprate lawyer could do) to keep a straight face. The judge was looking at him like he had worms crawling out his ears.......LOL To this day i send our attorney a picture of the Starman movie poster anytime a new suit comes in.....begging him that he try the "Starman Defense" this time.